The present invention relates to a speaker for automobile use of a waterproof structure which is assembled into an inside of a door of an automobile.
Generally, since this kind of speaker for automobile use is assembled into a position below a window glass inside a door of an automobile, waterproofing measure comes to be taken to prevent the rain water or car-washing water or the like, from getting into important vibration elements of the speaker along the window glass. Concrete examples thereof will be given hereafter.
FIG. 1 is a schematic cross sectional view to show a conventional ordinary automobile-mounted speaker, and FIG. 2 is an external view of FIG. 1. In the figures, reference numeral 1 denotes a frame of the automobile-mounted speaker. This frame 1 is formed into a trumpet shape having a plurality of openings 21-24. Reference numeral 3 denotes an outward-looking front-end flange which is integrally formed around a peripheral edge of a front-end opening. Reference numeral 4 denotes an annular wall portion bent from the rear end of the trumpet-shape part of the frame 1 in a diametrically inner direction so as to be positioned near the rear portion of the openings 21-24. This annular wall portion 4 serves as an area for adhering a damper thereto, which will be described later. Reference numeral 5 denotes a rear-end stepped portion which is bent from the inner peripheral edge portion of the annular wall portion 4 in an axially outward direction. At the rear-end peripheral portion of this rear-end annular stepped portion 5, there is formed an annular rear wall portion 6 which is bent in the diametrically inward direction.
Reference numeral 7 denotes a cone paper (vibrating diaphragm) whose peripheral edge portion is adhered to the front-end opening edge portion of the frame 1. Reference numeral 8 denotes the damper whose peripheral edge portion is adhered to a front face of the annular wall portion 4. The cone paper 7 and the damper 8 are integrally connected to a bobbin 9 at the respective central portions.
Reference numeral 10 denotes a magnetic circuit unit which is mounted on the rear wall portion 6 of the frame 1. This magnetic circuit unit 10 is to resonate the damper 8 and the cone paper 7 through the bobbin 9, and is made up of a ring-shaped magnet 11, first and second magnetic members 12, 13 which sandwich the magnet 11, and a voice coil 14. At this point the first magnetic member 12 is formed into a projected shape in cross section having a central axial portion 12a which is coaxial with the bobbin 9. The second magnetic member 13 is made of a ring plate which is fitted into the central axial portion 12a of the first magnetic member 12. The voice coil 14 is interposed between the central axial portion 12a and the second magnetic member 13. The voice coil 14 is arranged to be energized.
The speaker for automobile use having the above described arrangement is set in position by assembling the front-end flange 3 of the frame 1 to a metal plate below the window glass inside the door of the automobile. In order to cover the metal plate, an interior decorating plate is attached to the door, and an opening for the speaker in the interior decorating plate and the speaker having adhered thereto a gasket 15 are set in position close to each other.
Next, a description will now be made about the operation.
The sound is generated by a vibration of the cone paper 7 and the damper 8 through the bobbin 9 by means of audio current at the time of energization of the voice coil 14.
Since the conventional ordinary speaker for automobile use has the above described arrangement, there was a problem that the rain water or car-washing water which enters the inside of the door through the window glass of the door at the time of rainy weather or at the time of car washing, splashes onto the speaker thereby resulting in a deterioration of the speaker characteristics or performance.
In other words, the rain water or car-washing water is likely to enter from the openings 21-24 which are opened at the trumpet-shape part of the frame 1 (especially from the upper and left and right openings 21-23) so as to be positioned below the window glass of the automobile door. Due to water impregnation by the entered water into the water-absorbing cone paper 7 and the damper 8, there were problems that the resonance characteristics of the cone paper 7 and the damper 8 get deteriorated, that the amount of water impregnation gradually increases and the penetrated water finds its way into the magnetic circuit unit 10 to thereby generate abnormal noises, and that rust is formed inside the magnetic circuit unit 10.
In order to solve the above described problems, there has been proposed a speaker for automobile use with a waterproof cover.
FIG. 3 is a perspective view to show a conventional speaker for automobile use with a waterproof cover. The same reference numerals have been given to the same constituent parts as those in FIGS. 1 and 2 and further descriptions on them have been omitted. In FIG. 3, reference numeral 16 denotes the waterproof cover mounted on a rear side of the frame 1. This waterproof cover 16 covers the upper, left and right openings 21-23 which are formed in the trumpet-shape part of the frame 1 as shown in FIGS. 1 and 2, and also covers the magnetic circuit unit 10 in the rear portion.
By means of covering the rear side of the frame 1 with the waterproof cover 16 as described above, the rain water or the car-washing water that has entered the inside of the door along the window glass is prevented from splashing onto the essential vibrating elements of the speaker or from penetrating into the magnetic circuit unit 10 through the openings 21-23.
Since the conventional speaker for automobile use with the waterproof cover has the above described arrangement, there was a problem that the waterproof cover 16 which covered from the front-end flange 3 of the frame 1 to the rear end of the magnetic circuit unit 10 itself became large in size, thereby resulting in an increase of cost. Further, since the large-sized waterproof cover 16 becomes occupying larger area for the assembled speaker, there was a problem that the place for assembled speaker to be attached was limited.
As another example of conventional speaker with the waterproof cover, Laid Open Japanese Utility Model No. 42286/1995 discloses a speaker for automobile use with waterproof structure which does not require the waterproof cover portion of a separate constituent part. In this automobile-mounted speaker, a partial waterproof cover which shields a space between the upper opening of the frame and the upper edge portion of the damper by means of bending forward, is integrally formed on a substantially semicircular edge portion on the upper side of the damper-mounting wall portion of the frame which is formed into a trumpet-shape having a plurality of openings.
In this conventional example, however, substantially the entire surface of the damper-mounting wall portion of the frame serves as the damper adhering area. Since the upper edge portion of the damper which is adhered to the damper-mounting wall portion is positioned closely to the waterproof cover portion, the water splashing from the upper opening onto the waterproof cover portion or the water entering from the upper opening by splashing at the magnetic circuit unit, get included into the damper by rolling over the waterproof cover portion. As a result, a problem arises that there is a higher possibility of the speaker characteristics"" getting deteriorated by the wetting of the damper. Further, the waterproof cover portion is integrally formed only on the upper edge portion of the damper-mounting wall portion. Therefore, the orientation which the speaker can be mounted is restricted, and it requires an accuracy to mount the speaker. Therefore, there is a problem that the operability of mounting the speaker is lowered.
The present invention has been made to solve the above described and other problems, and it has an object to provide a speaker for automobile use by which the rain water or the car-washing water can be effectively prevented from splashing onto the essential speaker constituent parts without requiring a waterproof cover as a separate constituent part, and at the same time by which the operability for mounting the speaker is improved without restriction to the orientation for mounting the speaker.
Further, the present invention has an object to provide a speaker for automobile use which more effectively enhances the waterproofing property of the essential speaker constituent parts by means of partly closing the openings with the wall portion of the speaker frame itself without requiring the waterproof cover as a separate constituent part, and at the same time which also decreases the deterioration of the sound quality.
Still further, the present invention has an object to provide a speaker for automobile use in which the water penetrating into the bottom between the rear wall portion of the speaker frame and the damper are not accumulated there.
Furthermore, the present invention has an object to provide a speaker for automobile use in which the place for assembled speaker to be attached is not restricted by the waterproof member though the waterproof member is assembled as a separate constituent part, and at the same time the waterproof member can be easily mounted also on a conventional speaker.
A speaker for automobile use relating to the present invention a speaker for automobile use includes: a frame which is formed into a trumpet shape having a plurality of openings and which is provided on a small-diameter side of the trumpet-shape part with a damper-mounting wall portion extending in a diametrically inward direction; a damper whose peripheral edge portion is adhered to the damper-mounting wall portion; a vibrating diaphragm provided so as to extend over a front side of the frame; and a magnetic circuit unit which is mounted on a rear face side of the frame so as to vibrate the damper and the vibrating diaphragm; it is characterized in that the damper-mounting wall portion is formed with a diameter larger than a diameter of the damper, and that an annular eave-shaped barrier wall portion which axially extends toward the front side of the frame so as to enclose a circumference of the damper at a position away from the peripheral edge portion of the damper is integrally formed in a peripheral edge portion of the damper-mounting wall portion.
According to the speaker for automobile use having the above described arrangement, by the annular eave-shaped barrier wall portion which is formed integral with the damper-mounting wall portion of the frame, the rain water or the car-washing water entering the inside of the door of the automobile is prevented from splashing onto the damper through the openings of the frame. Therefore, a waterproof cover as a separate constituent part is eliminated, with the result that the cost is reduced and the size of the speaker is minimized, and also that the restriction on the place for assembled speaker to be attached can be alleviated. Still further, since the barrier wall portion having the above described arrangement does not restrict the orientation in which the speaker is mounted, there is an effect that the flexibility of the assembling of the speaker is improved.
Especially, the above described barrier wall portion is formed larger in outer diameter than the diameter of the adhered damper in the damper-mounting wall portion so as to enclose the damper at a position away from the outer peripheral portion of the damper. Therefore, a frequency is largely reduced that the water falling onto the barrier wall portion through the openings of the frame or the water entering through the openings by splashing on the magnetic circuit unit gets attached to the damper or to the vibrating diaphragm (cone paper). As a result, there is an effect that the deterioration of the speaker characteristics can be effectively prevented.
In the speaker for automobile use relating to the present invention, a barrier wall portion is formed substantially at a right angle to the damper-mounting portion of the frame.
According to the speaker for automobile use having the above described arrangement, there is an effect that the water falling through the openings of the frame onto the barrier wall portion or the water entering through the openings by splashing on the magnetic circuit unit is prevented from reaching the damper by the surface tension thereof along the barrier wall portion.
In the speaker for automobile use relating to the present invention, an upper side of the trumpet-shape part of the frame is formed as a cover wall portion free from an opening.
According to the speaker for automobile use having the above described arrangement, a larger area free from an opening can be secured at an upper side of the trumpet-shape portion of the frame. Therefore, there is an effect that the water is more effectively prevented from splashing from above the trumpet-shape part onto the damper or onto the vibrating diaphragm.
In the speaker for automobile use relating to the present invention, the frame is provided with openings which open at left, right and lower sides respectively, except at an upper side, of the trumpet-shape part, and the damper-mounting wall portion and the barrier wall portion are provided at each lower side thereof with a crena portion which is in continuation of the opening on the lower side.
According to the speaker for automobile use having the above described arrangement, while the upper-side wall portion of the trumpet-shape part of the frame can be utilized as a cover wall portion above the damper, the area of opening of the upper wall portion is reduced. However, due to the crena portions provided at the lower side of the respective damper-mounting wall portion and the barrier wall portion, the area of opening on the lower side is enlarged. Therefore, there is an effect that the deterioration of the sound quality is reduced. Furthermore, there is an effect that the water entering into the inside of the eave-shaped barrier wall portion can be discharged out of the crena portions.
A speaker for automobile use relating to the present invention includes: a frame which is formed into a trumpet shape having a plurality of openings and which is provided on a small-diameter side of the trumpet-shape part with a damper-mounting wall portion extending in a diametrically inward direction; a damper whose peripheral edge portion is adhered to the damper-mounting wall portion; a vibrating diaphragm provided so as to extend over a front side of the frame; and a magnetic circuit unit which is mounted on a rear face side of the frame so as to resonate the damper and the vibrating diaphragm; it is characterized in that on a rear side of the damper-mounting wall portion, there is assembled an annular waterproofing member having barrier piece portions each extending axially forward through each of the openings so as to intermittently enclose a circumference of the damper.
According to the speaker for automobile use having the above described arrangement, although the waterproof member as a separate constituent part is required, this waterproof member may be simple in shape and small in size and thereby it is assembled into the rear side of the damper-mounting wall portion so that the barrier piece portions are protruded forward through the openings. Therefore, there can be obtained an effect that the place for assembled speaker to be attached is not restricted by the waterproof member.
In the speaker for automobile use relating to the present invention, the waterproof member is held in position by insertion into an annular stepped portion which is formed in an inner peripheral edge portion of the damper-mounting wall portion and extending axially backward.
According to the speaker for automobile use having the above described arrangement, there is an effect that only by fitting the waterproof member into the annular stepped portion on the rear of the damper-mounting wall portion, the waterproofing member can be easily assembled into the frame.
In the speaker for automobile use relating to the present invention, the waterproof member has an annular peripheral wall portion and a fitting crena portion for fitting into each of supporting portions between respective openings of the frame are formed at the annular peripheral wall portion.
According to the speaker for automobile use having the above described arrangement, by fitting the crena portions of the waterproof member into the bridge wall portions of the frame, there is an effect that the peripheral wall portions of the waterproof member can be protruded forward respectively through the openings of the frame as barrier pieces for waterproofing the damper, and in addition, that the waterproofing member can be stably held in position by the frame in that state.